Among the light-induced herbicidal compounds represented by the general formula (I), 3-substituted phenylpyrazole derivatives represented by the general formula (I-1) are known compounds disclosed in Japanese Patent Laid-open Nos. Hei 3-163063 and Hei 4-211085, wherein it is mentioned that these compounds have, as herbicides for foliage treatment, an outstanding herbicidal activity on general broad-leaved weeds noxious in upland farming.
It is known that a number of compounds analogous to the chemical structure of the general formula (I-1) in the overall chemical structure and relative configuration of substituents exhibit a similar herbicidal activity as light-induced herbicides (Anderson et al., ACS Symposium Series, Vol. 559, Porphyric Pesticides, S. O. Duke and C. A. Robeiz eds., p. 18-34 (1994)). It is also known that a resistance to these light-induced herbicides can generally be given to plants by introducing a specific gene into the plants (International Patent Application WO98/29554).
On the other hand, organophosphorus herbicidal compounds such as N-(phosphonomethyl) glycine or salts thereof disclosed in Japanese Patent Laid-open Nos. Sho 47-39538 and Sho 57-98994, 4-[hydroxy(methyl)phosphino]-DL-homoalanine or salts thereof disclosed in Japanese Patent Laid-open No. Sho 57-26564 and 4-[hydroxy(methyl)phosphino]-L-homoalanyl-L-alanyl-L-alanine or salts thereof disclosed in Japanese Patent Laid-open No. Sho 50-23282, etc. are well known as non-selective herbicides for foliage treatment.
Further, Japanese Patent Laid-open No. Hei 7-242510 discloses herbicidal compositions containing a 3-substituted phenylpyrazole derivative and an organophosphorus herbicidal compound.
Further, Weed Sci. Soc. 25, (1977), p. 275-287 refers to an adjuvant effect of alkyl alcohol alkoxylates on N-(phosphonomethyl) glycine. However, this technique is insufficient in the adjuvant effect and the alkyl alcohol alkoxylates are not readily compatible with an aqueous solution of N-(phosphonomethyl) glycine.
Thus, it has been demanded to further improve the herbicidal effect and rapid action of a herbicidal composition containing a light-induced herbicidal compound, especially a 3-substituted phenylpyrazole derivative and an organophosphorus herbicidal compound.